Bus support capacitor, variable frequency driver electric control cabinet and central air conditioner

Abstract

The invention relates to a bus support capacitor, a variable frequency driver electric control cabinet and a central air conditioner, and the bus support capacitor is characterized in that a plurality of capacitor cores are connected in parallel and then are arranged in a unified housing, and a traditional loose structure that a plurality of independent cylindrical capacitors are externally connected in parallel is replaced, so that the space utilization rate is greatly improved; therefore, the capacitor module is smaller in size and more compact in structure, is convenient to arrange in a frequency converter electric control cabinet with limited space, and meets the requirements of miniaturization and integration of modern equipment. Moreover, the integrated structure enables the heat generated by the capacitor core to be more effectively conducted to the housing through the busbar assembly and the internal potting material. The optimized thermal management allows the capacitor to bear larger current in unit volume, and the operating temperature is lower, so that the load capacity of the product is improved, and the service life of the product is prolonged.

Description

Technical Field

[0001] This invention relates to the technical field of power electronic components, specifically to a busbar support capacitor, a frequency converter driver control cabinet, and a central air conditioner. Background Technology

[0002] Large central air conditioning systems are widely used in public places such as shopping malls, airports, and train stations, as well as in industrial projects. The demand for high and stable power supply is increasing. Among them, the busbar support film capacitor is a key component, which needs to have high capacity and low inductance characteristics to ensure stable and efficient power supply.

[0003] Busbar-supported film capacitors act as "stabilizers" or "reservoirs" in large central air conditioning power systems. Their core function is to stabilize DC voltage and filter high-frequency harmonic interference. In power electronics, a "busbar" usually refers to the main power supply line, which can be understood as the "main artery" or "traffic artery" of a circuit, responsible for transmitting powerful current; here, it specifically refers to the DC busbar. Just as bridge piers support the bridge deck, busbar-supported film capacitors are connected in parallel to the DC busbar, providing voltage support and preventing drastic voltage fluctuations. The dielectric of busbar-supported film capacitors is a plastic film (such as PP, PET, etc.). This type of capacitor has advantages such as long lifespan, high reliability, and good high-frequency characteristics, making it very suitable for the frequently changing operating conditions of air conditioning inverter drives.

[0004] The busbar-supported film capacitor is not installed at the air conditioning terminals visible to users (such as air vents), but rather inside the core power component of the central air conditioning system—the electrical control cabinet, specifically within the DC circuit of the inverter driver. For the applicant's central air conditioning system using magnetic levitation technology, this capacitor is a key component of the magnetic levitation inverter centrifugal compressor drive module. The busbar-supported film capacitor can be visualized as a rectangular metal box with multiple large copper terminals (pins), tightly connected to other power units inside the inverter driver (such as IGBT modules) via thick copper busbars (busbars).

[0005] To summarize the positional relationship of the busbar supporting the film capacitor: Central air conditioning unit -> Compressor unit -> Variable frequency drive control cabinet -> DC bus circuit -> Bus support film capacitor.

[0006] Therefore, although this component is inconspicuous, it is the heart of the system, ensuring the efficient, stable, and reliable operation of the magnetic levitation central air conditioning system. The applicant must invest in research and development to improve it, as its performance directly affects the competitiveness and reliability of the entire product.

[0007] Traditional solutions typically use multiple cylindrical aluminum-cased DC-Link capacitors connected in parallel. While this method boasts a mature manufacturing process, it suffers from significant drawbacks: high stray inductance, large installation space requirements, and cumbersome installation steps. For a traditional solution, assuming we need a system consisting of four cylindrical capacitors connected in parallel (the actual number would be much greater in practice), the installation process would be as follows: Step 1: Prepare 4 independent cylindrical capacitors (C1, C2, C3, C4), each with two leads: positive (+) and negative (-).

[0008] Step 2: Make two copper busbars: one is the positive busbar and the other is the negative busbar.

[0009] Step 3: Use bolts to secure the positive terminals of C1, C2, C3, and C4 to the positive busbar.

[0010] Step 4: Similarly, connect all their negative terminals to the negative busbar. This completes the parallel connection of the four capacitors.

[0011] Step 5: Secure the entire array to the base plate of the electrical control cabinet one by one with screws.

[0012] Step Six: Connect the ends of the positive and negative busbars to the other parts of the system.

[0013] In traditional designs, current needs to flow through a long, circuitous busbar path from one capacitor to another. Each bolt connection point and each section of the busbar generates additional parasitic inductance (stray inductance). During high-frequency switching (such as IGBT fast turn-on / off), large stray inductances can generate high voltage spikes, leading to reduced system efficiency (heating), severe electromagnetic interference, and even component breakdown. Space needs to be allocated between each cylinder for installation and wiring, and the busbars themselves also take up space. The entire array is very loose, resulting in extremely low space utilization.

[0014] During installation, each capacitor needs to be installed and secured individually, and all bolts need to be tightened one by one (a very large number). This process is complex, time-consuming, labor-intensive, and has a low degree of automation. The leads of each capacitor are directly fixed to the aluminum shell. During transportation or installation, if subjected to external force or due to stress release from the shell, the leads of individual capacitors may slightly deform or shift, leading to misalignment when installing the busbars, causing installation difficulties or poor contact. Summary of the Invention

[0015] In view of this, the purpose of the present invention is to provide a busbar support capacitor, a frequency converter drive control cabinet and a central air conditioner, so as to solve the problem that the existing busbar support capacitor requires dozens of independent cylindrical capacitors connected in parallel, which occupy a large area in the control cabinet through external busbars, bolts and mounting brackets, and has low integration.

[0016] According to a first aspect of the present invention, a busbar-supported capacitor is provided, comprising: The housing, and a plurality of capacitor cores connected in parallel disposed within the housing; The busbar assembly has terminals soldered onto it, and the positive and negative terminals of the capacitor core are soldered onto the busbar assembly, forming a signal circuit through the busbar assembly and the terminals.

[0017] Preferably, the busbar assembly includes: A positive and negative busbar are symmetrically and parallelly arranged inside the housing, and the positive and negative busbars are made of conductive material; The ends of the positive busbar and the negative busbar are insulated and fixed together by a positioning epoxy plate. The wiring terminals are welded to the positioning epoxy board.

[0018] Preferably, the positive busbar and the negative busbar are the same size; Multiple capacitor cores in each column have their gold-plated end faces spatially aligned, with one end soldered to a common positive busbar and the other end soldered to a common negative busbar, forming a parallel connection.

[0019] Preferably, the surfaces of the positive and negative busbars are provided with multiple metal points for soldering to the end faces of the gold plating layer of the capacitor core, and each metal point has the same shape and size.

[0020] Preferably, each column of capacitor cores corresponds to two columns of metal points, and each capacitor core corresponds to two metal points; The terminal block includes four terminals, two of which correspond to the positive terminal of the capacitor and two of which correspond to the negative terminal of the capacitor.

[0021] Preferably, the busbar-supported capacitor further includes: Multiple heat dissipation holes are evenly distributed around the metal points; The location of the heat dissipation holes corresponds to the gaps formed between the stacked capacitor cores.

[0022] Preferably, the busbar-supported capacitor further includes: A positioning epoxy cover, with openings at both ends, is installed around the positive and negative busbars and the positioning epoxy plate.

[0023] Preferably, a waist hole is provided on the top side wall of the outer casing, and a fixing ear is detachably installed in the waist hole; The mounting height of the fixing ear is higher than the mounting height of the bottom of the terminal block.

[0024] Preferably, the waist hole is elliptical, and the fixing ear is triangular; and / or, The outer casing is made of 304 stainless steel.

[0025] Preferably, a grounding screw is fixed to the bottom of the housing for connection to the grounding busbar.

[0026] Preferably, the busbar-supported capacitor further includes: A potting compound is used to fill all remaining voids inside the housing, encapsulating all internal components except for the terminals into a cured whole.

[0027] According to a second aspect of the present invention, a DC bus circuit is provided, comprising: The aforementioned busbar supports the capacitor.

[0028] According to a third aspect of the present invention, a variable frequency drive control cabinet is provided, comprising: The aforementioned DC bus circuit.

[0029] According to a fourth aspect of the present invention, a central air conditioning system is provided, comprising: The compressor and the aforementioned variable frequency drive control cabinet.

[0030] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects: First, by integrating multiple capacitor cores in parallel into a single unified housing, replacing the traditional loose structure of multiple independent cylindrical capacitors connected externally, space utilization is greatly improved. This results in smaller, more compact capacitor modules, facilitating their placement within space-constrained inverter control cabinets and meeting the miniaturization and integration requirements of modern equipment. Furthermore, the integrated structure allows heat generated by the capacitor cores to be more effectively conducted to the housing through the busbar assembly and internal potting material. Optimized thermal management allows the capacitors to carry greater current per unit volume and operate at lower temperatures, thereby enhancing the product's load capacity and lifespan.

[0031] Secondly, the use of busbar assemblies as a unified internal current collection and distribution channel replaces the lengthy and circuitous external busbars and multiple bolt connection points found in traditional solutions. Busbar assemblies offer superior current paths and electromagnetic characteristics, effectively reducing parasitic parameters (especially stray inductance). Low stray inductance can suppress voltage spikes and electromagnetic interference generated during the switching of power devices (such as IGBTs), improving the overall energy efficiency and operational reliability of the system.

[0032] Furthermore, the capacitor core is connected to the busbar assembly using soldering, and the busbar assembly is also soldered to the external terminals. Compared to traditional bolted connections, soldered connections have lower and more stable contact resistance, higher mechanical strength, and avoid bolt loosening and poor contact problems caused by vibration or thermal expansion and contraction. This results in more consistent electrical performance and a longer lifespan for the capacitor.

[0033] Furthermore, the capacitors are supplied as a complete modular unit, with all internal cores connected in parallel and packaged before leaving the factory. For the customer, installation only requires connecting a few terminals to the system, eliminating the tedious work of installing, paralleling, and wiring individual capacitors. This greatly reduces installation time and the risk of human error, facilitates automated production, and lowers overall manufacturing costs.

[0034] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0035] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0036] Figure 1 This is an exploded view of a busbar-supported capacitor according to an exemplary embodiment; Figure 2 This is an enlarged schematic diagram of a partial structure of the capacitor core in a busbar-supported capacitor according to an exemplary embodiment; Figure 3 This is a cross-sectional view of a busbar-supported capacitor according to an exemplary embodiment; Figure 4 This is a front view of a busbar-supported capacitor according to an exemplary embodiment; Figure 5 This is a side view of a busbar-supported capacitor according to an exemplary embodiment. Detailed Implementation

[0037] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0038] Example 1 Figure 1 This is an exploded view of a busbar-supported capacitor according to an exemplary embodiment, such as... Figure 1 As shown, the busbar-supported capacitor includes: The outer casing 7, and a plurality of capacitor cores 5 connected in parallel within the outer casing 7; Busbar assembly 3, on which terminals 1 are soldered, and the positive and negative terminals of capacitor core 5 are respectively soldered to busbar assembly 3, forming a signal circuit through busbar assembly 3 and terminals 1.

[0039] It should be noted that the technical solution provided in this embodiment is applicable to DC bus circuits, where the DC bus circuit is installed in the frequency converter control cabinet, which is a component of the central air conditioning unit.

[0040] Preferably, the busbar-supported capacitor further includes: A potting compound is used to fill all remaining gaps inside the housing 7, encapsulating all internal components except for the terminal block 1 into a cured whole.

[0041] Preferably, the busbar supporting capacitor is a film capacitor for a magnetic levitation motor. Stretchable plastic films such as PP / PET / PPS are rolled into film capacitor cores 5 through a series of capacitor manufacturing processes. Metal materials are then attached to the surface of the film capacitor cores 5 via spraying. The busbar assembly 3 is then connected to the capacitor cores 5 using special welding methods such as resistance welding or soldering. Multiple capacitor cores 5 are assembled into a housing 7 via the busbar assembly 3. Finally, the entire assembly is encapsulated inside the housing 7 using potting compound, completing the manufacturing process of a film capacitor for a magnetic levitation motor.

[0042] Preferably, see Figure 2 The capacitor core 5 has a flat structure and an end face that is drum-shaped.

[0043] Understandably, the "flat structure" is like replacing a thick book with multiple thin books laid flat. Its shape is more conducive to tight stacking within the flat outer shell 7, reducing the unusable space between the cylindrical cores. This allows for the maximum number of dielectrics (films) to be accommodated within the same outer shell 7 volume, thereby maximizing the capacitor's capacitance density (i.e., capacitance per unit volume). This is the most fundamental physical basis for achieving "large capacity, small volume".

[0044] In addition, the regular, flat surface makes it easy to position and align the cores when stacking and assembling them into the housing 7. This facilitates automated production, ensuring that each row of cores is placed into the housing 7 in a uniform and precise manner, thereby guaranteeing highly consistent electrical performance (such as inductance and resistance parameters) between different batches of products.

[0045] The "waist-drum shaped sides" naturally create regular, continuous ventilation channels (heat dissipation gaps) between rows when multiple cores are stacked in a row through the flat surfaces. These gaps provide channels for the flow and convection of potting compound (or air, depending on the process), efficiently conducting away the heat generated by each core during operation and preventing heat from accumulating in the center of the core array and forming a "heat island effect".

[0046] Compared to a pure rectangle, the waist drum-shaped design actually increases the side surface area of ​​a single core, providing a larger contact area for heat dissipation to the surrounding potting compound and the outer casing 7.

[0047] Furthermore, the smooth, drum-shaped end face (or side) avoids sharp right-angle edges. In high-voltage applications, sharp edges of conductors are prone to electric field concentration, leading to partial discharge and accelerated aging of the insulation material. The smooth, drum-shaped design allows for a more uniform electric field distribution, reducing electric field concentration effects and thus improving the product's withstand voltage rating and long-term electrical insulation reliability.

[0048] It is understandable that the technical solution provided in this embodiment, firstly, replaces the traditional loose structure of multiple independent cylindrical capacitors connected in parallel outside by integrating multiple capacitor cores 5 into a unified housing 7. This greatly improves space utilization, making the capacitor module smaller and more compact, facilitating its layout in space-constrained inverter control cabinets, and meeting the miniaturization and integration requirements of modern equipment. Furthermore, the integrated structure allows the heat generated by the capacitor cores 5 to be more effectively conducted to the housing 7 through the busbar assembly 3 and internal potting material. Optimized thermal management allows the capacitor to carry a larger current per unit volume and operate at a lower temperature, thereby improving the product's load capacity and service life.

[0049] Secondly, busbar assembly 3 is used as the internal unified current collection and distribution channel, replacing the long and circuitous external busbars and multiple bolt connection points in the traditional solution. Busbar assembly 3 has superior current path and electromagnetic characteristics, which can effectively reduce parasitic parameters (especially stray inductance). Low stray inductance can suppress voltage spikes and electromagnetic interference generated when power devices (such as IGBTs) switch, improving the overall energy efficiency and operational reliability of the system.

[0050] Furthermore, the capacitor core 5 is connected to the busbar assembly 3 by soldering, and the busbar assembly 3 is also soldered to the external terminal block 1. Compared to traditional bolted connections, soldered connections have lower and more stable contact resistance, higher mechanical strength, and avoid bolt loosening and poor contact problems caused by vibration or thermal expansion and contraction. This results in more consistent electrical performance and a longer lifespan for the capacitor.

[0051] Furthermore, the capacitors are supplied as a complete modular unit, with all internal cores connected in parallel and packaged before leaving the factory. For the customer, installation only requires connecting a few terminals 1 to the system, eliminating the tedious work of installing, paralleling, and wiring individual capacitors. This greatly reduces installation time and the risk of human error, facilitates automated production, and lowers overall manufacturing costs.

[0052] Example 2 A busbar-supported capacitor according to an exemplary embodiment includes: The outer casing 7, and a plurality of capacitor cores 5 connected in parallel within the outer casing 7; Busbar assembly 3, on which terminals 1 are soldered, and the positive and negative terminals of capacitor core 5 are respectively soldered to busbar assembly 3, forming a signal circuit through busbar assembly 3 and terminals 1.

[0053] Among them, see Figure 1 The busbar assembly 3 includes: A positive busbar and a negative busbar are symmetrically and parallelly arranged inside the housing 7, and the positive busbar and the negative busbar are made of conductive material; The ends of the positive busbar and the negative busbar are insulated and fixed together by a positioning epoxy plate 2. The wiring terminal 1 is welded onto the positioning epoxy plate 2.

[0054] It should be noted that the technical solution provided in this embodiment is applicable to DC bus circuits, where the DC bus circuit is installed in the frequency converter control cabinet, which is a component of the central air conditioning unit.

[0055] Preferably, the busbar-supported capacitor further includes: A potting compound is used to fill all remaining gaps inside the housing 7, encapsulating all internal components except for the terminal block 1 into a cured whole.

[0056] Preferably, the busbar-supported capacitor further includes: The lower end of the insulating post 8 is fixed to a protrusion / screw hole on the top edge or inner side of the housing 7, and the upper end of the insulating post 8 is in contact with or connected to the base of the terminal block 1. The core function of the insulating post 8 is to support and isolate the live parts from the grounded housing 7 in the vertical direction, thereby increasing the creepage distance.

[0057] Preferably, the busbar supporting capacitor is a film capacitor for a magnetic levitation motor. Stretchable plastic films such as PP / PET / PPS are rolled into film capacitor cores 5 through a series of capacitor manufacturing processes. Metal materials are then attached to the surface of the film capacitor cores 5 via spraying. The busbar assembly 3 is then connected to the capacitor cores 5 using special welding methods such as resistance welding or soldering. Multiple capacitor cores 5 are assembled into a housing 7 using the busbar assembly 3. Finally, the entire assembly is encapsulated inside the housing 7 using potting compound, completing the manufacturing process of a film capacitor for a magnetic levitation motor.

[0058] Preferably, see Figure 2 The capacitor core 5 has a flat structure and an end face that is drum-shaped.

[0059] Understandably, the "flat structure" is like replacing a thick book with multiple thin books laid flat. Its shape is more conducive to tight stacking within the flat outer shell 7, reducing the unusable space between the cylindrical cores. This allows for the maximum number of dielectrics (films) to be accommodated within the same outer shell 7 volume, thereby maximizing the capacitor's capacitance density (i.e., capacitance per unit volume). This is the most fundamental physical basis for achieving "large capacity, small volume".

[0060] In addition, the regular, flat surface makes it easy to position and align the cores when stacking and assembling them into the housing 7. This facilitates automated production, ensuring that each row of cores is placed into the housing 7 in a uniform and precise manner, thereby guaranteeing highly consistent electrical performance (such as inductance and resistance parameters) between different batches of products.

[0061] The "waist-drum shaped sides" naturally create regular, continuous ventilation channels (heat dissipation gaps) between rows when multiple cores are stacked in a row through the flat surfaces. These gaps provide channels for the flow and convection of potting compound (or air, depending on the process), efficiently conducting away the heat generated by each core during operation and preventing heat from accumulating in the center of the core array and forming a "heat island effect".

[0062] Compared to a pure rectangle, the waist drum-shaped design actually increases the side surface area of ​​a single core, providing a larger contact area for heat dissipation to the surrounding potting compound and the outer casing 7.

[0063] Furthermore, the smooth, drum-shaped end face (or side) avoids sharp right-angle edges. In high-voltage applications, sharp edges of conductors are prone to electric field concentration, leading to partial discharge and accelerated aging of the insulation material. The smooth, drum-shaped design allows for a more uniform electric field distribution, reducing electric field concentration effects and thus improving the product's withstand voltage rating and long-term electrical insulation reliability.

[0064] It is understood that, compared to Embodiment 1, this second embodiment explicitly specifies that the positive and negative busbars are symmetrically parallel and of the same size. This symmetrical structure ensures that the current inflow and return paths are completely mirrored. When currents of equal magnitude but opposite direction flow in the two closely parallel busbars, the magnetic fields they generate cancel each other out, thereby actively and maximally reducing the stray inductance of the circuit itself from a physical structural perspective. This differs from passively shortening the path; it fundamentally weakens the magnetic field effect. For high-frequency, high-current switching magnetic levitation motor drive systems, this significantly reduces voltage spikes and switching losses, improving system efficiency and stability.

[0065] Using the positioning epoxy board 2 as the core component, it simultaneously achieves the two functions of insulation and fixation. It is not only an insulating barrier between the ends of the positive and negative busbars, but also a robust "structural skeleton" that precisely fixes the two busbars in their relative positions. This rigid connection makes the busbar assembly 3 a robust integral module, which can effectively resist vibration and impact during transportation and use, prevent the busbars from shifting or deforming due to external forces or thermal expansion and contraction, and avoid stress cracking or poor contact at the connection points caused by these factors.

[0066] Even under harsh conditions, the positioning epoxy plate 2 ensures a safe electrical clearance and creepage distance between the positive and negative busbars, eliminating the possibility of short circuits and improving the long-term safety and reliability of the product. The positioning epoxy plate 2 provides a stable and flat reference surface for the welding process, avoiding incomplete welding or inaccurate positioning caused by busbar vibration at high welding temperatures.

[0067] In practice, the positive and negative busbars, the positioning epoxy board 2, and the terminal blocks 1 can be independently assembled into a robust, standardized busbar assembly 3 sub-module. This sub-module is then assembled with the capacitor core array 5 as a whole. This modular design simplifies the assembly process, facilitates automated production, ensures high consistency between different products, and reduces production costs and human error.

[0068] Example 3 A busbar-supported capacitor according to an exemplary embodiment includes: The outer casing 7, and a plurality of capacitor cores 5 connected in parallel within the outer casing 7; Busbar assembly 3, on which terminals 1 are soldered, and the positive and negative terminals of capacitor core 5 are respectively soldered to busbar assembly 3, forming a signal circuit through busbar assembly 3 and terminals 1.

[0069] The busbar assembly 3 includes: A positive busbar and a negative busbar are symmetrically and parallelly arranged inside the housing 7, and the positive busbar and the negative busbar are made of conductive material; The ends of the positive busbar and the negative busbar are insulated and fixed together by a positioning epoxy plate 2. The wiring terminal 1 is welded onto the positioning epoxy plate 2.

[0070] See Figure 1 and Figure 3 The positive and negative busbars are the same size; Multiple capacitor cores 5 in each column have their end faces with gold plating 4 aligned in space, with one end soldered on a common positive busbar and the other end soldered on a common negative busbar, forming a parallel connection.

[0071] It should be noted that the technical solution provided in this embodiment is applicable to DC bus circuits, where the DC bus circuit is installed in the frequency converter control cabinet, which is a component of the central air conditioning unit.

[0072] Preferably, the busbar-supported capacitor further includes: A potting compound is used to fill all remaining gaps inside the housing 7, encapsulating all internal components except for the terminal block 1 into a cured whole.

[0073] Preferably, the busbar supporting capacitor is a film capacitor for a magnetic levitation motor. Stretchable plastic films such as PP / PET / PPS are rolled into film capacitor cores 5 through a series of capacitor manufacturing processes. Metal materials are then attached to the surface of the film capacitor cores 5 via spraying. The busbar assembly 3 is then connected to the capacitor cores 5 using special welding methods such as resistance welding or soldering. Multiple capacitor cores 5 are assembled into a housing 7 using the busbar assembly 3. Finally, the entire assembly is encapsulated inside the housing 7 using potting compound, completing the manufacturing process of a film capacitor for a magnetic levitation motor.

[0074] Preferably, see Figure 2 The capacitor core 5 has a flat structure and an end face that is drum-shaped.

[0075] Understandably, the "flat structure" is like replacing a thick book with multiple thin books laid flat. Its shape is more conducive to tight stacking within the flat outer shell 7, reducing the unusable space between the cylindrical cores. This allows for the maximum number of dielectrics (films) to be accommodated within the same outer shell 7 volume, thereby maximizing the capacitor's capacitance density (i.e., capacitance per unit volume). This is the most fundamental physical basis for achieving "large capacity, small volume".

[0076] In addition, the regular, flat surface makes it easy to position and align the cores when stacking and assembling them into the housing 7. This facilitates automated production, ensuring that each row of cores is placed into the housing 7 in a uniform and precise manner, thereby guaranteeing highly consistent electrical performance (such as inductance and resistance parameters) between different batches of products.

[0077] The "waist-drum shaped sides" naturally create regular, continuous ventilation channels (heat dissipation gaps) between rows when multiple cores are stacked in a row through the flat surfaces. These gaps provide channels for the flow and convection of potting compound (or air, depending on the process), efficiently conducting away the heat generated by each core during operation and preventing heat from accumulating in the center of the core array and forming a "heat island effect".

[0078] Compared to a pure rectangle, the waist drum-shaped design actually increases the side surface area of ​​a single core, providing a larger contact area for heat dissipation to the surrounding potting compound and the outer casing 7.

[0079] Furthermore, the smooth, drum-shaped end face (or side) avoids sharp right-angle edges. In high-voltage applications, sharp edges of conductors are prone to electric field concentration, leading to partial discharge and accelerated aging of the insulation material. The smooth, drum-shaped design allows for a more uniform electric field distribution, reducing electric field concentration effects and thus improving the product's withstand voltage rating and long-term electrical insulation reliability.

[0080] Understandably, in Embodiment 3, compared to Embodiment 2, the positive and negative busbars are of the same size and aligned with the end faces of the cores. This ensures that the current flow paths into (positive) and out (negative) have completely symmetrical geometry and cross-sectional area. This is one of the most effective methods to reduce stray inductance. According to the principle of electromagnetic induction, when currents of equal magnitude and opposite direction flow in two symmetrical and adjacent conductors, the magnetic fields they generate cancel each other out. This actively and maximally weakens the magnetic field effect of the current loop from a physical structure perspective, thereby minimizing the stray inductance of the loop. For high-frequency switching inverters, this can significantly reduce voltage spikes and switching losses, improving system efficiency and EMC (electromagnetic compatibility) performance.

[0081] All positive terminals of each row of capacitor cores are welded to a common positive busbar, and all negative terminals are welded to a common negative busbar. This "common busbar" connection provides the shortest and most impedance-consistent path for current. Current can be evenly distributed to each capacitor core, preventing overload in individual cores due to uneven path impedance. Simultaneously, the shortest path and the largest conductor cross-sectional area significantly reduce the overall equivalent series resistance (ESR) of the capacitor, thereby reducing conduction losses and heat generation during current flow, improving energy efficiency and capacitor reliability.

[0082] "The spatial alignment of the end faces of multiple capacitor cores 5 with gold plating layer 4 in each column" is a prerequisite for achieving current sharing. Precise alignment ensures that the welding length and contact resistance of each core to the busbar are basically consistent. This ensures that the current shared by each capacitor core 5 connected in parallel is highly uniform. Excellent current sharing prevents individual cores from aging prematurely due to overcurrent, making the lifespan of all cores synchronized, thereby significantly extending the service life of the entire capacitor module.

[0083] Example 4 A busbar-supported capacitor according to an exemplary embodiment includes: The outer casing 7, and a plurality of capacitor cores 5 connected in parallel within the outer casing 7; Busbar assembly 3, on which terminals 1 are soldered, and the positive and negative terminals of capacitor core 5 are respectively soldered to busbar assembly 3, forming a signal circuit through busbar assembly 3 and terminals 1.

[0084] The busbar assembly 3 includes: A positive busbar and a negative busbar are symmetrically and parallelly arranged inside the housing 7, and the positive busbar and the negative busbar are made of conductive material; The ends of the positive busbar and the negative busbar are insulated and fixed together by a positioning epoxy plate 2. The wiring terminal 1 is welded onto the positioning epoxy plate 2.

[0085] See Figure 1 and Figure 3 The positive and negative busbars are the same size; Multiple capacitor cores 5 in each column have their end faces with gold plating 4 aligned in space, with one end soldered on a common positive busbar and the other end soldered on a common negative busbar, forming a parallel connection.

[0086] In practical application, see Figure 1 The positive and negative busbars are provided with multiple metal points on their surfaces for soldering to the end face of the gold-plated layer 4 of the capacitor core 5. Each metal point has the same shape and size.

[0087] Preferably, each column of capacitor cores 5 corresponds to two columns of metal points, and each capacitor core 5 corresponds to two metal points; The terminal block 1 includes four terminals, two of which correspond to the positive terminal of the capacitor and two of which correspond to the negative terminal of the capacitor.

[0088] See Figure 3 Terminals A and C are on the same pole, and terminals B and D are on the same pole. The terminals are connected to the busbar assembly 3 by welding, and the busbar assembly 3 is connected to the capacitor core 5 by soldering.

[0089] It should be noted that the technical solution provided in this embodiment is applicable to DC bus circuits, where the DC bus circuit is installed in the frequency converter control cabinet, which is a component of the central air conditioning unit.

[0090] Preferably, the busbar-supported capacitor further includes: A potting compound is used to fill all remaining gaps inside the housing 7, encapsulating all internal components except for the terminal block 1 into a cured whole.

[0091] Preferably, the busbar supporting capacitor is a film capacitor for a magnetic levitation motor. Stretchable plastic films such as PP / PET / PPS are rolled into film capacitor cores 5 through a series of capacitor manufacturing processes. Metal materials are then attached to the surface of the film capacitor cores 5 via spraying. The busbar assembly 3 is then connected to the capacitor cores 5 using special welding methods such as resistance welding or soldering. Multiple capacitor cores 5 are assembled into a housing 7 using the busbar assembly 3. Finally, the entire assembly is encapsulated inside the housing 7 using potting compound, completing the manufacturing process of a film capacitor for a magnetic levitation motor.

[0092] Preferably, see Figure 2 The capacitor core 5 has a flat structure and an end face that is drum-shaped.

[0093] Understandably, the "flat structure" is like replacing a thick book with multiple thin books laid flat. Its shape is more conducive to tight stacking within the flat outer shell 7, reducing the unusable space between the cylindrical cores. This allows for the maximum number of dielectrics (films) to be accommodated within the same outer shell 7 volume, thereby maximizing the capacitor's capacitance density (i.e., capacitance per unit volume). This is the most fundamental physical basis for achieving "large capacity, small volume".

[0094] In addition, the regular, flat surface makes it easy to position and align the cores when stacking and assembling them into the housing 7. This facilitates automated production, ensuring that each row of cores is placed into the housing 7 in a uniform and precise manner, thereby guaranteeing highly consistent electrical performance (such as inductance and resistance parameters) between different batches of products.

[0095] The "waist-drum shaped sides" naturally create regular, continuous ventilation channels (heat dissipation gaps) between rows when multiple cores are stacked in a row through the flat surfaces. These gaps provide channels for the flow and convection of potting compound (or air, depending on the process), efficiently conducting away the heat generated by each core during operation and preventing heat from accumulating in the center of the core array and forming a "heat island effect".

[0096] Compared to a pure rectangle, the waist drum-shaped design actually increases the side surface area of ​​a single core, providing a larger contact area for heat dissipation to the surrounding potting compound and the outer casing 7.

[0097] Furthermore, the smooth, drum-shaped end face (or side) avoids sharp right-angle edges. In high-voltage applications, sharp edges of conductors are prone to electric field concentration, leading to partial discharge and accelerated aging of the insulation material. The smooth, drum-shaped design allows for a more uniform electric field distribution, reducing electric field concentration effects and thus improving the product's withstand voltage rating and long-term electrical insulation reliability.

[0098] It is understood that, compared to Example 3, in this fourth embodiment, the busbar surface is provided with metal dots of the same shape and size, and the dots are arranged regularly (two dots for each column of cores). The uniform pad design provides ideal conditions for automated soldering equipment (such as solder paste printers, pick-and-place machines, and reflow ovens), realizing the standardization and precise control of the soldering process.

[0099] Furthermore, the identical heat capacity and welding area of ​​each weld point ensure consistent weld strength and quality across all connections, preventing damage from incomplete welds, cold welds, or overheating caused by inconsistent weld point sizes. This design significantly simplifies the manufacturing process, reduces the uncertainty of human intervention, facilitates large-scale production, and substantially improves production efficiency and product yield, thereby reducing manufacturing costs.

[0100] Furthermore, each capacitor core 5 is connected to two metal points. This dual-point connection provides two parallel paths for the current, effectively reducing the current density and contact resistance at a single connection point. Simultaneously, the doubled solder area significantly improves heat dissipation from the core end face to the busbar. The two solder points share the load, making the connection between the core and the busbar more robust and better resistant to fatigue caused by vibration and thermal stress, greatly reducing the risk of connection failure. This is crucial for industrial applications requiring high reliability.

[0101] Understandably, when capacitors are installed in a frequency converter system, even if one terminal connection becomes loose in extreme cases, the other terminal can still ensure the continuity of electrical connection, providing valuable redundancy for the system and enhancing fault tolerance, making it especially suitable for critical occasions where downtime is not allowed.

[0102] Example 5 A busbar-supported capacitor according to an exemplary embodiment includes: The outer casing 7, and a plurality of capacitor cores 5 connected in parallel within the outer casing 7; Busbar assembly 3, on which terminals 1 are soldered, and the positive and negative terminals of capacitor core 5 are respectively soldered to busbar assembly 3, forming a signal circuit through busbar assembly 3 and terminals 1.

[0103] The busbar assembly 3 includes: A positive busbar and a negative busbar are symmetrically and parallelly arranged inside the housing 7, and the positive busbar and the negative busbar are made of conductive material; The ends of the positive busbar and the negative busbar are insulated and fixed together by a positioning epoxy plate 2. The wiring terminal 1 is welded onto the positioning epoxy plate 2.

[0104] See Figure 1 and Figure 3 The positive and negative busbars are the same size; Multiple capacitor cores 5 in each column have their end faces with gold plating 4 aligned in space, with one end soldered on a common positive busbar and the other end soldered on a common negative busbar, forming a parallel connection.

[0105] In practical application, see Figure 1 The positive and negative busbars are provided with multiple metal points on their surfaces for soldering to the end face of the gold-plated layer 4 of the capacitor core 5. Each metal point has the same shape and size.

[0106] Each column of capacitor core 5 corresponds to two columns of metal points, and each capacitor core 5 corresponds to two metal points; The terminal block 1 includes four terminals, two of which correspond to the positive terminal of the capacitor and two of which correspond to the negative terminal of the capacitor.

[0107] See Figure 1 The busbar-supported capacitor further includes: Multiple heat dissipation holes are evenly distributed around the metal points; The position of the heat dissipation hole corresponds to the gap formed between the stacked capacitor cores 5.

[0108] It should be noted that the technical solution provided in this embodiment is applicable to DC bus circuits, where the DC bus circuit is installed in the frequency converter control cabinet, which is a component of the central air conditioning unit.

[0109] Preferably, the busbar-supported capacitor further includes: A potting compound is used to fill all remaining gaps inside the housing 7, encapsulating all internal components except for the terminal block 1 into a cured whole.

[0110] Preferably, the busbar supporting capacitor is a film capacitor for a magnetic levitation motor. Stretchable plastic films such as PP / PET / PPS are rolled into film capacitor cores 5 through a series of capacitor manufacturing processes. Metal materials are then attached to the surface of the film capacitor cores 5 via spraying. The busbar assembly 3 is then connected to the capacitor cores 5 using special welding methods such as resistance welding or soldering. Multiple capacitor cores 5 are assembled into a housing 7 using the busbar assembly 3. Finally, the entire assembly is encapsulated inside the housing 7 using potting compound, completing the manufacturing process of a film capacitor for a magnetic levitation motor.

[0111] Preferably, see Figure 2 The capacitor core 5 has a flat structure and an end face that is drum-shaped.

[0112] Understandably, the "flat structure" is like replacing a thick book with multiple thin books laid flat. Its shape is more conducive to tight stacking within the flat outer shell 7, reducing the unusable space between the cylindrical cores. This allows for the maximum number of dielectrics (films) to be accommodated within the same outer shell 7 volume, thereby maximizing the capacitor's capacitance density (i.e., capacitance per unit volume). This is the most fundamental physical basis for achieving "large capacity, small volume".

[0113] In addition, the regular, flat surface makes it easy to position and align the cores when stacking and assembling them into the housing 7. This facilitates automated production, ensuring that each row of cores is placed into the housing 7 in a uniform and precise manner, thereby guaranteeing highly consistent electrical performance (such as inductance and resistance parameters) between different batches of products.

[0114] The "waist-drum shaped sides" naturally create regular, continuous ventilation channels (heat dissipation gaps) between rows when multiple cores are stacked in a row through the flat surfaces. These gaps provide channels for the flow and convection of potting compound (or air, depending on the process), efficiently conducting away the heat generated by each core during operation and preventing heat from accumulating in the center of the core array and forming a "heat island effect".

[0115] Compared to a pure rectangle, the waist drum-shaped design actually increases the side surface area of ​​a single core, providing a larger contact area for heat dissipation to the surrounding potting compound and the outer casing 7.

[0116] Furthermore, the smooth, drum-shaped end face (or side) avoids sharp right-angle edges. In high-voltage applications, sharp edges of conductors are prone to electric field concentration, leading to partial discharge and accelerated aging of the insulation material. The smooth, drum-shaped design allows for a more uniform electric field distribution, reducing electric field concentration effects and thus improving the product's withstand voltage rating and long-term electrical insulation reliability.

[0117] It is understandable that, compared to Embodiment 4, the position of the heat dissipation holes in Embodiment 5 precisely corresponds to the gap formed by the stacking of capacitor cores 5. The heat generated when the capacitor core 5 is working is first conducted to the metal points of the busbar through the gold-plated layer 4 on its surface. This heat can be immediately transferred directly to the potting compound filled in the holes through the heat dissipation holes around the points, and then quickly conducted to the entire outer casing 7 through the potting compound, and finally dissipated into the air by the large heat dissipation surface of the outer casing 7.

[0118] During frequent charging and discharging and temperature cycling of capacitors, the busbar undergoes thermal expansion and contraction. Evenly distributed heat dissipation holes can prevent large thermal stress concentrations in localized areas due to excessive temperature differences, reducing the risk of busbar material cracking due to stress fatigue, thereby improving the reliability of the product under long-term alternating heat loads.

[0119] This design effectively prevents heat from being trapped in the localized area between the core and the busbar, solving the problem of this area easily becoming a heat dissipation bottleneck in traditional structures, and significantly reducing the hot spot temperature at the connection between the core and the busbar. This is crucial for ensuring the long-term reliability of the solder joint and extending the capacitor's lifespan.

[0120] In addition, the multiple heat dissipation holes evenly distributed on the busbar provide channels for the liquid potting compound to flow vertically during the potting process. The potting compound can smoothly pass through these holes and fully fill all the spaces above and below the busbar, especially the tiny gaps inside the capacitor core array 5, avoiding air bubbles or voids caused by the inability of gas to escape, thus ensuring the density and integrity of the potting.

[0121] After the potting compound cures, these sections penetrating the heat dissipation holes act like countless "rivets" or "anchors," firmly locking the busbar in the center of the potting compound. This greatly enhances the busbar's vibration and impact resistance, preventing it from loosening or deforming due to long-term stress.

[0122] Preferably, see Figure 1 The busbar-supported capacitor further includes: The positioning epoxy cover 11 has openings at both ends and covers the periphery of the positive busbar, the negative busbar, and the positioning epoxy plate 2.

[0123] Understandably, the positioning epoxy cover 11 is made of insulating material and acts as an additional insulating shell 7, completely enclosing the entire energized busbar assembly 3 (positive busbar, negative busbar, and their connection points). Even in extreme cases (such as when internal components detach due to failure or when there are defects in the potting compound), the cover effectively prevents short circuits between the positive and negative busbars, avoiding catastrophic internal arcing.

[0124] It provides double insulation protection (potting compound + epoxy cover 11) between the internal high-potential busbar and the external grounded casing 7, significantly increasing the creepage distance and ensuring the long-term insulation reliability of the product in harsh environments such as high voltage and high humidity, preventing breakdown of the casing 7.

[0125] In addition, it provides an integrated positioning reference for both the busbar assembly 3 and the terminal block 1. During assembly, simply insert the terminal block into the through hole on the top of the cover and snap the busbar assembly 3 into the cover to quickly and accurately align all key components, simplifying the assembly process and reducing human error.

[0126] Preferably, see Figure 1 , Figure 3 , Figure 4 and Figure 5 A waist hole 10 is provided on the top side wall of the outer shell 7, and a fixing ear 6 is detachably installed in the waist hole 10; The mounting height of the fixing ear 6 is higher than the mounting height of the bottom of the terminal block 1.

[0127] Preferably, the waist hole 10 is elliptical, and the fixing ear 6 is triangular; and / or, The outer casing 7 is made of 304 stainless steel.

[0128] Understandably, the mounting lug 6 is detachably mounted on the side wall of the housing 7 via an elliptical slot 10, which allows the mounting lug 6 to move within a certain range in the vertical direction. This allows for easy alignment of the mounting lug 6 when installing capacitors into the equipment cabinet, even with minor deviations in the position of the mounting studs on the cabinet. This solves the misalignment problem caused by processing or installation errors, improving installation efficiency and fault tolerance.

[0129] The detachable design means that if the mounting lug 6 itself is damaged, or if a different mounting method is needed, it can be removed separately for repair or replacement without scrapping the entire capacitor, thus reducing future maintenance costs.

[0130] The mounting height of the fixing ear 6 is higher than the mounting height of the bottom of the terminal block 1. When the fixing ear 6 is tightened with screws, the main tightening force and the resulting mechanical stress will act directly on the sturdy housing 7 and the fixing ear 6. Because the fixing ear 6 is positioned higher, the stress is distributed above the terminal connection point, effectively preventing the tightening force from acting directly on the fragile terminal block 1 and its solder joint with the busbar.

[0131] This design avoids internal damage such as terminal bending and solder joint cracking caused by over-tightening or improper installation, greatly improving the reliability of electrical connections.

[0132] Furthermore, the triangle is one of the most stable shapes in mechanical structures. The triangular mounting lug 6 provides a larger support area, distributing the weight and vibration load of the capacitor more evenly across the housing 7, making it more robust and durable than simple strip or round lugs, and less prone to deformation.

[0133] Furthermore, 304 stainless steel possesses significantly higher mechanical strength than ordinary aluminum shells, enabling it to better withstand installation and fastening forces and impacts during transportation. Simultaneously, it boasts exceptional corrosion resistance, allowing it to adapt to potentially humid and chlorine-containing environments such as central air conditioning machine rooms, preventing performance degradation or safety hazards caused by shell corrosion. The stainless steel shell is also resistant to deformation after forming, ensuring the product's appearance and dimensional stability, thus contributing to long-term reliability.

[0134] Preferably, a grounding screw 9 is fixed to the bottom of the outer casing 7 for connection to the grounding busbar.

[0135] Understandably, the grounding screw 9 is pre-fixed (e.g., welded) to the bottom of the casing 7, providing a dedicated grounding connection point. It permanently and reliably connects the capacitor's metal casing 7 to the system's grounding bus (i.e., earth potential). In the event of an internal insulation failure causing the casing 7 to become energized, current will immediately flow through this low-impedance path to the ground, triggering the system's leakage current protection device (such as a circuit breaker) to quickly cut off power, effectively preventing electric shock accidents and equipment damage, thus achieving intrinsic safety.

[0136] During daily operation, it can discharge static electricity that may accumulate on the outer casing 7 and filter out high-frequency electromagnetic interference, ensuring the stable operation of other parts of the system.

[0137] The capacitor is typically secured primarily by the top mounting lug 6. The bottom grounding screw 9 is also tightened to the mounting plate with a nut during installation, forming a two-point support structure with the top mounting lug 6. This support method greatly enhances the mechanical stability of the capacitor within the cabinet, effectively resisting vibrations and impacts generated during transportation, installation, and operation, preventing capacitor swaying, tilting, or loosening of connections, and improving long-term operational reliability.

[0138] The grounding screw 9 provides a standardized grounding interface. Installers do not need to find additional grounding locations or process connection points; they simply connect the grounding screw 9 to the cabinet's grounding busbar using a wire and nut. The operation is simple and the connection is secure. Compared to temporary grounding methods that may produce oxide layers or poor contact, this screw connection ensures low resistance and long-term reliability of the grounding loop.

[0139] Example 6 A DC bus circuit according to an exemplary embodiment includes: The aforementioned busbar supports the capacitor.

[0140] It is understood that the technical solution provided in this embodiment, including the aforementioned busbar-supported capacitor, firstly, by integrating multiple capacitor cores in parallel into a unified housing, replaces the loose structure of multiple independent cylindrical capacitors connected externally, greatly improving space utilization. This results in a smaller, more compact capacitor module, facilitating its layout within space-constrained inverter control cabinets and meeting the miniaturization and integration requirements of modern equipment. Furthermore, the integrated structure allows heat generated by the capacitor cores to be more effectively conducted to the housing through the busbar assembly and internal potting material. Optimized thermal management allows the capacitor to carry a larger current per unit volume and operate at a lower temperature, thereby improving the product's load capacity and service life.

[0141] Secondly, the use of busbar assemblies as a unified internal current collection and distribution channel replaces the lengthy and circuitous external busbars and multiple bolt connection points found in traditional solutions. Busbar assemblies offer superior current paths and electromagnetic characteristics, effectively reducing parasitic parameters (especially stray inductance). Low stray inductance can suppress voltage spikes and electromagnetic interference generated during the switching of power devices (such as IGBTs), improving the overall energy efficiency and operational reliability of the system.

[0142] Furthermore, the capacitor core is connected to the busbar assembly using soldering, and the busbar assembly is also soldered to the external terminals. Compared to traditional bolted connections, soldered connections have lower and more stable contact resistance, higher mechanical strength, and avoid bolt loosening and poor contact problems caused by vibration or thermal expansion and contraction. This results in more consistent electrical performance and a longer lifespan for the capacitor.

[0143] Furthermore, the capacitors are supplied as a complete modular unit, with all internal cores connected in parallel and packaged before leaving the factory. For the customer, installation only requires connecting a few terminals to the system, eliminating the tedious work of installing, paralleling, and wiring individual capacitors. This greatly reduces installation time and the risk of human error, facilitates automated production, and lowers overall manufacturing costs.

[0144] Example 7 An exemplary embodiment of a variable frequency drive control cabinet is shown, comprising: The aforementioned DC bus circuit.

[0145] It is understood that the technical solution provided in this embodiment, which includes the aforementioned busbar-supported capacitor, firstly, by integrating multiple capacitor cores in parallel into a unified housing, replaces the loose structure of multiple independent cylindrical capacitors connected externally. This significantly improves space utilization, making the capacitor module smaller and more compact, facilitating its layout within space-constrained inverter control cabinets, and meeting the miniaturization and integration requirements of modern equipment. Furthermore, the integrated structure allows the heat generated by the capacitor cores to be more effectively conducted to the housing through the busbar assembly and internal potting material. Optimized thermal management allows the capacitor to carry a larger current per unit volume and operate at a lower temperature, thereby improving the product's load capacity and service life.

[0146] Secondly, the use of busbar assemblies as a unified internal current collection and distribution channel replaces the lengthy and circuitous external busbars and multiple bolt connection points found in traditional solutions. Busbar assemblies offer superior current paths and electromagnetic characteristics, effectively reducing parasitic parameters (especially stray inductance). Low stray inductance can suppress voltage spikes and electromagnetic interference generated during the switching of power devices (such as IGBTs), improving the overall energy efficiency and operational reliability of the system.

[0147] Furthermore, the capacitor core is connected to the busbar assembly using soldering, and the busbar assembly is also soldered to the external terminals. Compared to traditional bolted connections, soldered connections have lower and more stable contact resistance, higher mechanical strength, and avoid bolt loosening and poor contact problems caused by vibration or thermal expansion and contraction. This results in more consistent electrical performance and a longer lifespan for the capacitor.

[0148] Furthermore, the capacitors are supplied as a complete modular unit, with all internal cores connected in parallel and packaged before leaving the factory. For the customer, installation only requires connecting a few terminals to the system, eliminating the tedious work of installing, paralleling, and wiring individual capacitors. This greatly reduces installation time and the risk of human error, facilitates automated production, and lowers overall manufacturing costs.

[0149] Example 8 A central air conditioning system according to an exemplary embodiment includes: The compressor and the aforementioned variable frequency drive control cabinet.

[0150] It is understood that the technical solution provided in this embodiment, which includes the aforementioned busbar-supported capacitor, firstly, by integrating multiple capacitor cores in parallel into a unified housing, replaces the loose structure of multiple independent cylindrical capacitors connected externally. This significantly improves space utilization, making the capacitor module smaller and more compact, facilitating its layout within space-constrained inverter control cabinets, and meeting the miniaturization and integration requirements of modern equipment. Furthermore, the integrated structure allows the heat generated by the capacitor cores to be more effectively conducted to the housing through the busbar assembly and internal potting material. Optimized thermal management allows the capacitor to carry a larger current per unit volume and operate at a lower temperature, thereby improving the product's load capacity and service life.

[0151] Secondly, the use of busbar assemblies as a unified internal current collection and distribution channel replaces the lengthy and circuitous external busbars and multiple bolt connection points found in traditional solutions. Busbar assemblies offer superior current paths and electromagnetic characteristics, effectively reducing parasitic parameters (especially stray inductance). Low stray inductance can suppress voltage spikes and electromagnetic interference generated during the switching of power devices (such as IGBTs), improving the overall energy efficiency and operational reliability of the system.

[0152] Furthermore, the capacitor core is connected to the busbar assembly using soldering, and the busbar assembly is also soldered to the external terminals. Compared to traditional bolted connections, soldered connections have lower and more stable contact resistance, higher mechanical strength, and avoid bolt loosening and poor contact problems caused by vibration or thermal expansion and contraction. This results in more consistent electrical performance and a longer lifespan for the capacitor.

[0153] Furthermore, the capacitors are supplied as a complete modular unit, with all internal cores connected in parallel and packaged before leaving the factory. For the customer, installation only requires connecting a few terminals to the system, eliminating the tedious work of installing, paralleling, and wiring individual capacitors. This greatly reduces installation time and the risk of human error, facilitates automated production, and lowers overall manufacturing costs.

[0154] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0155] It should be noted that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means at least two.

[0156] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0157] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0158] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0159] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0160] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0161] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0162] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A busbar support capacitor characterized by, The application relates to a busbar supporting capacitor. The application comprises: a shell, and a plurality of parallel capacitor cores arranged in the shell; 2. The busbar support capacitor of claim 1, wherein, a busbar assembly, a wiring terminal is welded on the busbar assembly, and the positive and negative poles of the capacitor cores are respectively soldered on the busbar assembly, so that a signal loop is formed through the busbar assembly and the wiring terminal. The busbar assembly comprises: a positive busbar and a negative busbar symmetrically and parallelly arranged in the shell, and the positive busbar and the negative busbar are made of conductive material; the end of the positive busbar and the end of the negative busbar are fixed and insulated through a positioning epoxy plate; the wiring terminal is welded on the positioning epoxy plate.

3. The busbar supporting capacitor according to claim 2, wherein: the positive busbar and the negative busbar are of the same size; a plurality of capacitor cores in each column have end faces with plating layers which are spatially aligned, one end of each capacitor core is soldered on the common positive busbar, and the other end of each capacitor core is soldered on the common negative busbar, so that the capacitor cores are connected in parallel.

4. The busbar supporting capacitor according to claim 3, wherein: the surfaces of the positive busbar and the negative busbar are provided with a plurality of metal points for soldering with the end faces of the plating layers of the capacitor cores, and each metal point is of the same shape and size.

5. The busbar supporting capacitor according to claim 4, wherein: each column of capacitor cores corresponds to two columns of metal points, and each capacitor core corresponds to two metal points; 6. The busbar support capacitor of claim 4, wherein, the wiring terminal comprises four, two of which correspond to the positive poles of the capacitors, and the other two of which correspond to the negative poles of the capacitors. Further comprising: a plurality of heat dissipation holes are uniformly arranged around the metal points; 7. The busbar support capacitor of claim 2, wherein, the positions of the heat dissipation holes correspond to the gaps formed between the capacitor cores when the capacitor cores are overlapped. Further comprising: a positioning epoxy cover which is open at both ends and covers the periphery of the positive busbar, the negative busbar and the positioning epoxy plate.

8. The busbar supporting capacitor according to any one of claims 1-7, wherein: a waist hole is formed in the top side wall of the shell, and a fixing lug is detachably mounted in the waist hole; the mounting height of the fixing lug is higher than the mounting height of the bottom of the wiring terminal.

9. The busbar supporting capacitor according to claim 8, wherein: the waist hole is oval, and the fixing lug is triangular; and / or the shell is made of 304 stainless steel.

10. The busbar supporting capacitor according to claim 8, wherein:

11. The busbar support capacitor of claim 8, wherein, a grounding screw is fixed to the bottom of the shell and used for connecting with a grounding busbar. Further comprising:

12. A direct current bus circuit, characterized by potting glue which is filled in all the remaining gaps in the shell and wraps all the internal elements except the wiring terminal into a solid whole. The application relates to a busbar supporting capacitor.

13. A variable frequency drive electrical control cabinet, characterized in that, The application relates to a DC bus circuit. The application relates to a compressor and a variable frequency driver electric control cabinet.

14. A central air conditioner, characterized by comprising: The application relates to a busbar supporting capacitor. ​

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